SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'aaf8676694d2e4392637944795a95cb16db263e8a2bedd452ec0c4e74c9640a4' 
  AND token = '+VvQk41u/D57VOR1cZyLhflvDqWsgvzXKPh1+rBXVNI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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