SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '496e009cf4fbf412787653a9dae6b9c1863956360843470115cd07b82ef81041' 
  AND token = 'iKqduHzOXKmBfTFJ5eiKgwSeZ94eQO24WwiPGixIcvo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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