SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '26a596f6730e578d2140abc183b3bf7949ad11751de7a6894c90e5c441be5373' 
  AND token = 'YylN2HdToKgqrfLy/h5cATAWfZQ+q3eHUg1wKq7egi8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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