SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4954a181ef94ecf8a6dd39fefc29b0907ba577caf729a8a752b191bdc11739c0' 
  AND token = 'zOuqZTknQQnNuXta5iNQJqCAEuqfsCeJ+fROHfzF/LA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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