SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '08970d58a4500921f7c985ac227a24264d32ac1293e79daa5dd79159eb2f44c4' 
  AND token = 'f4NoEo3GPssj/D4lgSKWCTmZbRw38Vl4HM7q8oiZUuE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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