SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8d96813f54af9b3ba6dd32c9da1e35e27d5dc98c2265ff3d7872981b6a6bbe87' 
  AND token = 'r6eOrdL/KiIMCJPqX5aJQvIpzvjmhj9N5eIFDeTNI7w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00010

JSON explain

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