SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0d37414d37be3c91a53eff4e6db9da51b057ed903b1df9f8dd23e08330e2f0cc' 
  AND token = 'y7pmgBwqLlBuHRSglSaLl3WW4nqcJAIwcFAX7Ylf+2I=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00047

JSON explain

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