SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f7832d90cc82f347b7fd2993972670ca18def942d244ab5a1628f0f0ad2318f6' 
  AND token = 'zC59RsfCJQDOOWhmst87TUGPRHwLNiksIEUEjYOQDQg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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