SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '26222abe5860feae2f3aa2d3830089597276d9a4c79b3c5cfb81b9a8230d99a8' 
  AND token = 'QFEjqAEGPWT9bBuo52g/zKZU8mwXMCX3QYMulRBiJ74=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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