SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '6598b23ca136cb65eee91dc1af1a513e29275c5f3adab3d2b0a3d7721478cfe8' 
  AND token = 'Wlb2sxeWJjgJGaNf9nfEKwdLB/QjIpHohzIVktX0lBQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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