SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0c534dad328bad35c31e3024f4c43e530d94790227c486f6b32d345f71f016be' 
  AND token = '6PQTSSaW1iBFPhW+jUbxTdOQvKcK+acbAoma0LtLERM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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