SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2fb27520b2c3676866957ee82e0ec80b4c077e2879563475a8104d1f445eda61' 
  AND token = 'YBpVZTqYj6lS8+Vuu6o+/Ay3pRzql8j6HM6zshT3qzU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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