SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '8b2505af4f095bff6186d831586e9d6feef6fe9337cb9d4242b0d33aeb41ed2a' 
  AND token = 'XQySWwR29le5LDEXmF3sgz5SXllKVkz9xSeTf2+85UE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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