SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1d8c1513c65c4eaa2c4ebec6bd010ef508c438c75aa32c8bf63c401f32b50b3c' 
  AND token = 'rojpuUA0n2nzoxFHlFMyMT0oCs9kreUtt/gwcSRsrZk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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