SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bab2a5948370a0722659af1d7f812dcc897b8f2d4d596d27969934f3fea06979' 
  AND token = '2CEZy9xDLWFLcrVH+pJMWAwSJPrXZJovW2SeaK0mHf8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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