SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4bed3af50140915cb8dbed5e3a785e17147b4f58a393239bf19e9de66e718f54' 
  AND token = 'jBEGwr8OkRaLxZl9xngXHkNy54d9ff+OLSkAEh3aqfk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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