SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '19758315056c15e52f302f624f2b053afbdcd31113cff4653eece3bc1c20c627' 
  AND token = 'sr4R7tGSFmUU5DK6r4Q9WtoKRJOJiK38v6Kt6ZPxrgY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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