SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'a661afa873b3496439735f18ce78377da6726ae0d876b3cd3dade577dc7dff84' 
  AND token = 'rwwz/P/+Y0zKCpZdSQVJvexYU9F9eeoCwQhCLg0VHsE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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