SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'f0ed53f10092129e66405ed993ca8d866e538922f4fb265871fe6241792c64e9' 
  AND token = 'iIz6wbaPURQrS+7MHQ1M7KaGxdRC6qwsmEaG1jvW4nM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00049

JSON explain

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