Sandbox

SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b68b2d6df0f8b565d04c2c691d59308369d139d9a7ec58d6f1eac1b484438139' 
  AND token = 'IRNCkseTxt6sgzOv5utQwpDbd5nDaTFtcb68PuKU+kU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00053

JSON explain

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