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SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fe0ce5daed3eca8ffd2d1dc6e8eafcdae971ec26746b0f8d582a90a31cfa0afa' 
  AND token = 'pHmkhfrspZnEivzEVHQKLmw38mAjkyvEhH1G9ODiLKE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}