SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '68f4bbb7ac4d0ba94d291c9bf70775f5001db224b09ff32b81ddc31959538a84' 
  AND token = 'J6ALKi2GSvy0mamH1N5vkliItZQXApttBwtiRn8qCV4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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