SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '97739c683d057c903280073bcbeb4c06391c5553d452d4ee9abcc90498a12dfb' 
  AND token = '3fAfeSyuf6aXOY6pCNVvgzPQhH2flJpqs16/GbABiRg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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