SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8d320fc1e37169530b1f1e2c9d9db27fc0a28c1ba6d6ba8f6e9f21540bdc8de1' 
  AND token = 'qmf6xdkFLTqdRqMEZNyCbMwA+cwOMR5osychIs/SFdY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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