SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '65ef5321d34326ea579ecb66a98c8d6b5a82bf5f3f963389514979cdf8bf30f4' 
  AND token = '8H02iXD4Mh7rFY3wpSqDb21S9SgUptpcy4MQqd2OpII=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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