SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '0a0890efb3fafb38108e22251dbb7ce9fdd32ab89e0e58acf93c906e5be68742' 
  AND token = 'MUN8/QlonOg2OJxZJ0zqmPjVVLfwAflKAAyaptbFPWo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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