SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '7fe3a5728fc7a77d3e95386e760f31b5d54ddd15c099b2eebf9ab0c023e03e54' 
  AND token = 'n9cBN+soueaQmw9lt9lCeRBRTvETIzbqF/+rNdGzUrg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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