SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '035c208638fbca14ae7ca4ee287bb67e007ee16e72ff2b6a25b4c6c8be4bc8fc' 
  AND token = 'MNBiXgYu3IriFxYvAp6sj5VqI7viL5pStI3GLn+GF9E=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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