SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e2aa0549b7d99b1acac2bd0658f328ee5ef248a1eb1072775f096b280d963e96' 
  AND token = 'ETGPJyxWu8f1YXYfiIZdzWufwkQUNrIqJpi6boD6V5Y=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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