SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '111d95cb8040c98ea0d4c4d53e2d2f5269ebd6252340786f996b6a5174de9d1c' 
  AND token = '79KL1mf0xV9PaOSA6s9/iAMaZKtGoRjxX5at93hui5I=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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