SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c0f0c23b8da03430f709f5025550e2883e929fa5e528b15c4a9636b9f956540f' 
  AND token = 'E0R8NBLHUMu5D660sHrtsJj/oY6pQ2FFPyC5kOEGI8E=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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