SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'cd64cdc8687fbab61de6618871205e149a13b303983896749c67fcb3f1e77fc3' 
  AND token = 'ACovYIjW0/IlInZhFjzGtHw/NfEB9yVefBOkAlGwUCA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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