SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f685e22e88f5b70dc078a2e1029e7cb3314c3d5fbcfd302e422262dea2f97a9b' 
  AND token = 'CgiQKIExyBXq1CrK48a+zH8a75124QTKtLu8enfRXAE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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