SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a5701076e08182abf071fc0c80e0c1e7903f92993e0e66be2f6753436d89afd8' 
  AND token = 'Zus4nzJXDhzZZJPiRjhY8ddGSRIP55gr4HH0olJ4HyM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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