SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a140597ec7f9cdcc16742efd0b3a2c4ffca924fda9152bead9e4a290d3785019' 
  AND token = 'YQMY6raFnMhmozhrIo7XYqRaYyeSDtc4WG/Rzg4CQlo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}