SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3d34a92d05f8fd399db08487e7cfe7ee9e53118ea10af32d3acd0bca1e17e65b' 
  AND token = 'Mhjjx8z5LqjZo5+Mot9ILbYxnWhUi0h/sLBlGPwECSk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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