SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '99417a00d52146abd8f178cb7247239f2bea93fcde6b0e45aba8adab1156df52' 
  AND token = 'LcBsichybOgdpJx5rIOeYHeUbnWaXSnfab65ItmfxDk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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