SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '86f29ea23e160134e67a26ec50d94784f8a2376c765acbbb499c1adf883d9cd6' 
  AND token = '+MZapei7YlBqFf+Nq4e5UVCOE3mfwfRLjlW5I/iXNTw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}