SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a4ba05ed3b371bb4659135344ec18d35cfcf3d39b789fecdbfacde89311ca7ec' 
  AND token = 'DIPMeLohcNCYKhWY/i0NdRawwYAS1qdRfRk1LKuOS+8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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