SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bb00fe50a4b27c9d4d251ca9761f8947e07f224b3dff3fb20f90d1fae31b6190' 
  AND token = 'zds+bOzu6v32+O5M8zrXYT4YK0+AEtFy84qFoFPhjy8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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