SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3f25dae43a7b862cb888c44106e980f6ae2ffc225b38864535b5462675e36d11' 
  AND token = 'YrKWCFKrvn4f41SbQv89cH4/5hvJvTevIDroBLgpPSk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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