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SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1878423e85009e313d5fda4e5c54527fbed6bcdee27a5b0eeb0ef320bd7663e1' 
  AND token = 'KiKpzFT6ujWZ9zBGNR7cSu1znmSD8HMwcodiQ7SYT1Y=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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