SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '97e09672581a796a582d1c3309e6e16c4103a6c1b9d26b5d2bb2161a960b6010' 
  AND token = 'XUy7HQ7UxHQmnaEJP0+QsqiYbylTsJOKl/mshhy06d4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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