SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e19a0b5571beffcb9f3b622e4920428a0053ca847e92a0d25af508380b72fc94' 
  AND token = 'TD+y6EkVRBhVJgznveE5kqgyqbbDEVJeKxQ5gLQW/eA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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