SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8fd5c16e9aa2a46c5509db9e183cdec7cf14b776765042fa65b18725a7e7ac6e' 
  AND token = 'LYwQyh5bDwNCBSJBsiElY0B2XJBhPUULsaSudlvdoQM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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