SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ac232079b0932feb1d555e6f609f101841c3223088d2d99d031a416ba679245d' 
  AND token = 'QFrH4gD85SDiyEKc23G/KcoY0aWRu3MKUoYu3avu8LU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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