SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'aa1872f7de19826c486777d77546fe00eb1e8b0895509b04c3d289a17e3efdf8' 
  AND token = 'IvBXkDpWLW7qCgAVPosCuoc/XFi2btWawGj0XM6M6zQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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