SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a6261dcf679657dc1b637e95a9568424825ce2bd3cac6d57d35a1029494103d1' 
  AND token = '+k49bmlotLt6r4BJ5Bn+wV/8pqgDrDVHpvECGle6jPs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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