SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'db028c0fadfcadd32346e975d1cb613426d0484fb56c92234f195e2b36491cb9' 
  AND token = '7o/d4oY2En5JbkoOe9x2+xcvkVqpMY1VkEEr/rkQWMk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

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