SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ccfe1aa403282130140f3cbab1ca32072d1e6a65b8f45d5a90fc67e2d65977cd' 
  AND token = 'bxbwujOLVONv6xLhZ+b/Lu4dE/BpABdKL39Fgnfj8Ew=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00045

JSON explain

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