SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'df500b34b127a3f149c99802a050013b7a68cf323f115d61625f3bcd56f6c2c1' 
  AND token = 'vjLtT+kaKSJtO+dE5WwMQA+5et1QAIgk9kHLhZCmpxw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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