SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3a8d53cc19d534cb190f5822ba7a78cb974d163a259001ab51fc1fd9358000cf' 
  AND token = 'yExy9Ps9bbRZKjn6DX7o2PjY39eEE0i7mXF0+pOruko=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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