SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '727cbb4788b57c81aa443f87a07a2196033f5c373b2c5489f5747bdeff1c4a8b' 
  AND token = '6QXYrI3qkc8kIowzwKjPRFwBdEPg48y02xRVVnzlzmc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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