SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1c1b267be3b0bc15802d1c351806c3d17dfcbd17e2387f117a74a37783a4cb90' 
  AND token = 'hMLcJIdE4hD7nUbn/TGoHYRAx8RFmvqO8tQvVn1vNWI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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