SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fcbfd09ab4e28908748a54021fcb0c7f4766996c3e20706301a3ca6dd2bbf01f' 
  AND token = '5sLNaDrLoLzWlj0yL0uwukDOFes1Z4y9meZ1QHyqs2A=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00045

JSON explain

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