Sandbox

SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6f73c9d6d085ef1c4d8a5da59bffa6c7879b5d881a53d9da6cffade7838c6253' 
  AND token = 'MbbQ8lQEUI72cPD8e4n6ZdwlxKNvbQTf2B6FhLy9uqo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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