SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'd08ebb1de784b9b6114ffb4aff7bc163329d84f133fdedff85b58fb47687f8d6' 
  AND token = 'PYuPpJRG6E2x/XiPrZcjQ7DIXWzJFKcAanGMEm0Gsag=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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