SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5f65d562019403862a0c03a3402e29dc827a96248cab413dbbc68598c3f9dffb' 
  AND token = 'qTtCkkV5Xhz255i03vlEGyH0RVBBytXmUuvfjYu0H7Q=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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