SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0435a170cdbcae59bccb411e8a22570edceeb25be369375655c748a247bb4d35' 
  AND token = 'YhYtNIZnxQpKPmEmvi6eEAtD6LJ0UL1FX1LzAbytPJQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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