SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e7d8e4972341a75f9d398f74652e14fa7da4d9076925c76ae35994a96756954b' 
  AND token = 'TCybOxqpfU2rI2ktVRKGRNJRSMgKQy7biylILKnWHes=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00015

JSON explain

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