SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd229ac8742d4897a3bed94189648e1847d88ea1325b1d3c3ada87a79b31cbbfd' 
  AND token = 'hcZXZPbgiIuzd+Xk9A2FR+eQWOKDRXkIIyjEgcKnRwE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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