SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5b9327b26546cf731f04f2acc8ca10509fa2b1bf80a8d6397f27c73ce5ac00ee' 
  AND token = 'osAmqq7VNPv4DWMmK+MdXmzYhhgBwGWWfXXd9dMGQX8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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