SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c1b6ab774b67dd04a37504679108acf08f7b302f87da4f2cc8b0df806048668e' 
  AND token = 'aVx5xRiDTeDvQJX4rqUl2rrhRW4qoO/q5b3d20VDmiY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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