SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '860acb0f8ee131bcf0cd93c16c3ce014715fc6c096530e6b65c2efbea14fc043' 
  AND token = 'a2Se0+iecZfdheueJ15/D7JL2hGPikke3KLYXItbgxU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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