SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b37a3183310db57b78a7237cac44e623cd8dfd87d175ebfebc8af3b0fcb6a5c6' 
  AND token = 'BJPVsPXTJ6RhFUK4g/T0t/BVZWL1eQbN0JdS9zGt0Xw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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