SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '65379187e711fbff86ecd657ad564458e55f4bcb17aae4e3ab266daff07ee0e3' 
  AND token = '5Hof8hBfYA7JpWilLsrSXdhQT4+S/96bGLwFmLQ9Sic=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}