SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ae3755e4e110549f4cce7148ef7649dff50c7de1b3080b4a4ecd243056e6748c' 
  AND token = 'wywOeec++1wAOQwILy7XobfNhyayZg/YbuL5zeifJcM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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