SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a1230a82df9722420aa529a527460f6f11882469067148d3cd61a1c342a0695d' 
  AND token = '69aX5xXHDkAh4Ep8RCphyjNeXVTd/Hrj07xWXY7TgfM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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