SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '29c3065f0982dfca71bc73a8c75c55fc8f3b1c91bbbd73dab1a41a7fa2e26b28' 
  AND token = '5oyVNlPlCDnodzXfkPvwi4RXHVyTpqwP7CJLkfLHglI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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