SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '655b2729bfe81d207a616e108d5ba4092497b29e177a0ed008df1a021cdb3ef0' 
  AND token = 'vQxFd36KaLvD/j4E45/F92sfDduDJ15gQIx2/Uqfbqg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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