SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b44095a877157085d0bbed65f2b4578717cf13b92be9fdeb7bf36cf7999af373' 
  AND token = 'gIjX4zYfNhz2LwQ+s3KPkTf1qJQQ3CorhkRFWSs1umE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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