SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6c172693c67d0aeacf6ec99e67a839914c13a48e70f38f4af6d48a295bb6f2b5' 
  AND token = 'tqApPb8/aI0uksMs2dtwS1ieEYm2RMj5dLtepGPkths=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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