SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '80ab8204d528f07431f8b972650e6687a1f3207671eff7485321a6c4f4c0d410' 
  AND token = 'GJD5nXT22Ty6soPg3VBFY1cO0n6S4V9/0meD9g/c5J0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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