SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd43f06004e577c05347a3fe6c10922239cd44761ee779d93701870c5a6c04e6b' 
  AND token = 'xvTBHaW4MbHhTRQdcqKnv7sGl0zs6HilmQIXnumRj1U=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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