SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '875a10d22765bbed1313a8cc9ebc9c6beb65f7ea1a415e42103e44bb7cf49a92' 
  AND token = 'hzA5u+mUyxqorNjXr6/dBxH4KZxHR1BYMrNTMh471wI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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