SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9286b0f5db2749ef7fb491defaed11838230958341fee48789250bd086201855' 
  AND token = 'PhgR00XFwDBUzewS/dWJdUQ9HBq2qawewMnW5VkmOUU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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