SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1a97693e9bdb62a79894f73dfb36009014a532c12bc292a921228f6911e50479' 
  AND token = 'P5MYHXwCIfLiKBZdnsyC/bW8GKgoS5gqYCEf9qj8VrA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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