SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '6fec83223cec204fb9cdfc4ba2181e247b9d9130d13bfc817f44d201269291e1' 
  AND token = 'XWczrrApFDWhiDzWzhk0rUiWfwDCYG/FBh+Fqhv6Mag=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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