SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'd263a2874c8cd0838ced51c7e5f2890326bd6bc511ef2b9861d7da4fb57a3d80' 
  AND token = 'YN4n4O9Ho9ZXBYH5Jx9SvFIq6qMjk6lVcV5D+iwR7FE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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