SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ad8e51576447724db792ce3b7d530981ccecbd98755ca46e9cf12b2550d85812' 
  AND token = '3Zuiml1WWE1clBco/+oQfJXGnMyaEqf+/kRUqFhiXjc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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