SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7a93b2e36eef2c20df1cedc89cc3655f111eee745da21b518655ad0b9bc3000c' 
  AND token = 'HbcctvKHwLxeCCqCPlmE9IwSjVNO3yBpBTwN9LFS7KA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

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