SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0dc0bb4fc566b0c83bdeb23a09f546fc671397f86eaa4dd9836a11a7f448295a' 
  AND token = 'uG1GJ+NUJjUB53JwoWGwFJmtmPBqJk/bHmOefBWTGTk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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