SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'd0f0ae6653466b8704612d3ac8a4593e0d974290cebb494d834c919a5e596314' 
  AND token = 'nAgUN+0wS380X9h1R7uKE6bs8QMyIGnMOHIe0PcLXj4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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