SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8630e66def1c5e1a7f79cab9c33dd99cf621270db79a5f42333b47346cbab4b8' 
  AND token = 'htbvBLAKALxMhXDVja5c4Y0s+P5meU1jj/r7JPQ/PPk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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