SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'd6ceefb1dc2d6da9b828030e1e3067e04a690c43244ef10aa1fa823b43bb85a5' 
  AND token = 'iqAbM4lElOSmVgJO99OwMLB8aYa4u/iMCw96npa95Ds=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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