SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '7c58d41ddc1c1a4aed7e34521d06c9531b30696507eef4b43f316b16644a429a' 
  AND token = '+QFk3DYsMqVYpoMYtOiEjUKVDg1P0oNDmZrrCD+du9Q=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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