SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '3fb5937f806e152fb23a1a2a6e11bdf44b86789b5404d14485a9aca1a30fa786' 
  AND token = 'XdFHi6g4TGh3luxK9xze+N1mK2op00Q8dNmZKJSW/uI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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