Sandbox

SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '51f2903edcc2225f56adce931f0dc8726085dee812476068ed082ad24590acdb' 
  AND token = 'YtYa5BGlhfUxn3Vv0vAXpks0RUkPDA1bG+nNWJg1VD0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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