SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '357a1fecfaebc9ebcd048f9e110616d962135ce3ef8afb8ef41cd421b90a7246' 
  AND token = 'AA5cQA5TFf3859LLLJqzB2tO0a2/kTnGNbiKpiS4wvw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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