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SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f4f3b43993788704f50d32ac8d0644fcf81dcaca303393fc6f3ea49ead1d7ab4' 
  AND token = 'uMtz+Rrkts3WahEfgTX07B4x5TO7/Mw7nJQYIwgBp5c=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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