SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '74861431766769eca5bc66e82faaea96ad83f7acc4a68e86b93a5d12590229a1' 
  AND token = 'fMrxD8KT+9pz2VQSU1nkJ6DxPGMBGa5Dqu+Xi+958zM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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