SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '3ab5e41ec421f67ee27d7e8cbab92afa952181af08f4db82d5d5b0f5dd61e1cd' 
  AND token = 'x2ztHyrpmfF2QSmtMVPEtBVm7hHwzYled4lQqRU9AH0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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