SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'cf28b175b4e8d7b40b90946633c92e87384b99d92f6387db44b792e1e252b9d0' 
  AND token = 'xxdv7wZxFR0fplvJnPIgMzgnwLG+yf+0LM2RJ6vEhiU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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