SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6c8772de19df98cb39f5ae6615e5a0f72802e99037d90cb2d79fc3de14ede2ec' 
  AND token = 'QpIGAVSwtwNeXqlHb01GSGqONd4Ld6C7paXyWyfMkm0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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