SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3b2972fee16bd66adb4f34fed05625d03648697be63450cc3f4dd7047e7fea16' 
  AND token = 'GxALQ5c+ho5ZsEhy0YSUqf4zLCtLKkePXROgfnTQcWU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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