SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'b7bc213ba8ebfbabad1e7240fce29b231391ef838a8a35495fce541344b79dab' 
  AND token = 'EUsJ8lpnfng82Ctjlmawjdf3qLjVGs4TvZ/BVSQ+Za8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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