SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '2e83a919188e12fde03a2789f3d97b8208ef92e5dba497614d6684ba26e60465' 
  AND token = 'OUqTQUPehZTdKXMtA4PcPjQ6omjIlA5kLZm+lkDSNHI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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