SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4f9a86a3a429be4391fc9a5c71bae379ae21a5322cfe7439a9cbd1c65c2f5ecc' 
  AND token = 'xeGuKs0+5+D+W0kj3Le+2pVhfNx9Rgp1lrZ/ryaN9x0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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