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SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f6f74887fc29871d6e5a0a9a72f46f29afa56b1316bbcf59fff2fe35cb63a4ec' 
  AND token = 'LBjpSZN4SXhF66V3jZoDWFz8dNc3XfYRCxVgbhzir38=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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