SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '10530c7bde972728790de6871e26849e55985abe4854b16c096a9bf9fd1b98bd' 
  AND token = 'vovvwcpKNUzZxCG2Ck6xkZTTM6ZBDkvFqF2rQulb1R8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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