SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3f3447d54fea3c8af15022809e5c7f4760129ce35b49f4ded53ae44f82e52cbb' 
  AND token = 'PGLlWm+tdzDsHxVITUuEysm/LMeFEgTKDJyBJANaI6Q=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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