SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1de1ad6a5869767f068bb178cb9494fed2795c48c653a3616887fc375594e4ce' 
  AND token = '7S52g+wi32Df85obUtwNSTbm6DuZRHteBNWSk441OcI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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