SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd0f2007eb8e7c84df9e9da6f4135effb2ebc8e8b568aacb971f1ab22a40a2e06' 
  AND token = 'z9HxSaw/nXjlqaPdsDGWexCMh3YSzrhhLZkD4JUwYOw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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