SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '5a77a8da38e96896fdd06133ec76f4eff0166449ec1aaa6fa96e4375becd12e1' 
  AND token = '26nKAgqFm28prbfo1gBzP2GeFumEJ248mW0SJ432roI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00063

JSON explain

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