SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '129c5df143241d8895be564b3d72232a2794b2226bef4722ea699156d9a83aec' 
  AND token = 'DMslwz6scv+F7zk2ic9hTQuJUlEC6pK+sGPW//oOInU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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